Pleat deformation control for pleated fluid treatment media

ABSTRACT

A continuous ribbon or fillet of an adhesive plastic, such as a hot melt adhesive, epoxy, or plastisol, adhered to selected areas of the internal surfaces and terminations of the pleats of an annular, inside-out flow longitudinally pleated fluid treatment medium, such as a fluid filter or coalescer medium, prevents pleat deformation and consequent &#39;&#39;&#39;&#39;pinch-off&#39;&#39;&#39;&#39; or blockage of the pleats when the medium is subjected to fluid pressure during use.

1451 Aug. 14, 1973 3,l89,l79 6/1965 McMichael.....................210/493 X 3,241,680 3/1966 Humbert, 210/484 PLEAT DEFORMATION CONTROLFOR PLEATED FLUID TREATMENT MEDIA [75] Inventor: James C. McLaren,Racine, Wis.

Primary Examiner-Samih N. Zahama Assistant Examiner-Richard W. BurksAttorney-Thomas E. Torphy [73] Assignee: Tenneco Inc., Racine, Wis.

Filed:

June 3, 1971 [57] ABSTRACT A continuous ribbon or fillet of an adhesiveplastic,

[21] Appl. No.: 149,508

521 U.S. 210/493, 210/497 such as a hot melt adhesive. p y or plastisol.[51] Int. B011! 27/06 hered to Selected areas of the internal surfacesand [58] Field 6: 55/478; 210/437, minations of the pleats of anannular, inside-out flow 210 4 4, 437 493 497 50 longitudinally pleatedfluid treatment medium, such as a fluid filter or coalescer medium,prevents pleat deformation and consequent pinch-off or blockage of thepleats when the medium is subjected to fluid pressure during use.

[56] References Cited UNITED STATES PATENTS 3,692,184 9/1972 Miller, Jr.et 210 493 x 3 246,765 4/1966 Murphy et al. 210 493 x 6 Claims, 6Drawing Figures PLEAT DEFORMATION CONTROL FOR PLEATED FLUID TREATMENTMEDIA BACKGROUND OF THE INVENTION This invention relates to a means tomaintain the pleats of a pleated fluid treatment medium assembled intoan inside-out flow fluid treatment unit in a desired position to assureoptimum performance of the fluid treatment unit during use.

Known prior art means for controlling the deformation of the pleats ofpleated fluid treatment media, such as pleated oil filter media and thelike, have generally been applied to those fluid treatment media placedin units in which the flow of fluid is from the outer surfaces of theannular element to the inside. Referring specifically to oil filters,such filter elements are commonly known as outside-in flow filterelements.

Outside-in flow filter elements generally consist of an annulus oflongitudinally pleated paper, which is the filter medium, having itsinner circumference supported by a perforated metal tube, commonlycalled the center tube. The outer circumference of the annular medium isoften surrounded by a perforated cylinder, also. This cylinder iscommonly called the outer shell. Each end of the annular medium andconcentric inner and outer shell assembly is sealed by a disc or cap,known to those skilled in the filter art as an end cap. At least one endcap has an opening in it to provide an outlet for fluid which flows fromthe outside to the inside of the filter element.

One prior art pleat deformation control means consists of bands of paperor lengths of string adhered to the external terminations or roots ofthe pleats at selected locations along the outer circumference of themedium. Such pleat deformation control means are shown in U.S. Pat. Nos.3,306,794 and 3,241,680 respectively.

A second prior art pleat deformation control means consists of placementof corrugated bands of relatively stiff paper adjacent the outercircumferential terminations and selected surface areas of the pleatsand adhered thereto or to the inner circumferential surface of the outershell. Such means are shown in U.S. Pat. Nos. 3,310,177 and 3,368,687.

It is known that extrusions of thermoplastic or thermosetting materialscan be applied as shown in U.S. Pat. No. 3,189,179 to pleated paperfilter media to maintain the pleats in a desired position. However, suchknown extrusions are only applied to the paper subsequent to its beingpleated and prior to its being formed into an annulus. This methodrequires that the pleated paper medium be maintained at a desired lengthduring the of th4e pleat deformation control ribbons or fillets onto thepaper. The paper medium with the extrusions thereon is then passedthrough an oven to effect curing and consequent-substantialsolidification of the extruded ribbons of pleat deformation controlmaterial. The pleated paper medium is then formed into an annulus forassembly into a filter ele' ment.

This latter prior art method of applying such extrusions prior toformation of the pleated paper medium into an annulus is cumbersome andexpensive. Use of other prior art means, such as supplemental corrugatedbands, also is cumbersome and expensive as such prior art pleatdeformation control means require additional time consuming labor and/oradditional, relatively costly materials.

SUMMARY OF THIS INVENTION This invention relates to a ribbon or filletof a plastic which serves as a pleat deformation controls means forannular pleated fluid treatment media.

As used herein plastic is defined as a substance that at some stage inits manufacture or processing can be shaped by flow (as by applicationof heat or pressure) with or without fillers, plasticizers, reinforcingagents, or other compounding ingredients and that can retain the newsolid often rigid shape under CONDI- TIONS of use.

BRIEF DESCRIPTION OF THE DRAWINGS 5 FIG. 1 is a segmented axialcross-sectional view normal to the longitudinal axis of a typicalinside-out flow pleated fluid treatment medium surrounded by acylindrical outer shell. The pleated fluid treatment media shown in thisfigure lacks pleat deformation control means and a consequent typicalpleat pinchof condition is illustrated;

FIG. 2 is a longitudinal cross-sectioanl view of a typical fluidtreatment unit or element having pleat deformation control ribbons orfillets of this invention applied to it FIG. 3 is a segmentedcross-sectional view taken on line 33 of FIG. 2;

FIG. 4 is a longitudinal cross-sectional view of a typical fluidtreatment unit or element having pleat deformation control ribbons orfillets of this invention applied in an alternate spiral configuration;

FIG. 5 shows typical apparatus used to apply the pleat deformationcontrol ribbons or fillets of this invention; and

FIG. 6 is a cross-sectional view taken on line 6-6 of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 only a portion of across-section normal to the longitudinal axis of a typical inside-outflow fluid treatment unit or element is shown. An annulus of pleatedfluid treatment medium 2 is placed within and surrounded by an outermetallic cylinder or shell 3 having fluid flow perforations or openings4. Each end of such a cylindrical element is sealed by an end cap.

The annulus of pleated fluid treatment medium, in FIG. 1 is a coalescingmedium, 2 has an inner circumference 5 and an outer circumference 6generally defined by internal pleat terminations 7 and external pleatterminations 8 respectively. The terminations are connected by a seriesof integral pleat legs 9. The pleated medium 2 is formed by pleatingstrips of sheet materials, such as paper, on conventional well knownpleaters, then cutting the strips of desired length and forming thestrips into an annulus and maintaining them in annular form by placingthe two ends 10 and 11 of the strip together and sealingly securing themwith a means, such as clip 12.

When a coalescing element such as that shown in FIG. 1 is placed inservice in a suitable apparatus, not shown, the fluid flows through themedium as indicated by arrows. When the medium is subjected to adifferential pressure due to the restriction to flow of the medium, thepleats have a tendency to deform. stiffening of media, such as paper byimpregnation or coating with resins has traditionally been used todecrease such deformation. However, the degree of stiffening obtainableis often not sufficient to withstand the pressure differential and thelegs 9 of the medium consequently are forced into contact with eachother as shown at 13. Therefore, the pleats become substantially pinchedoff or blocked and the resistance to flow of such pleats is markedlyincreased. This is a highly undesirable condition as it increased theresistance to flow of the entire medium which increases the pressuredifferential across the medium. Consequently, other pleats in the mediumtend to be deformed and pinched off also. In severe cases the resistanceto flow of the entire medium can become so large that the entire mediumbecomes substantially impervious to fluid flow, thus rendering the unitinoperative. Also, due to the greatly increased pressure differentialacross the medium, the medium may burst, thus rendering the unitinoperative.

FIG. 2 shows a longitudinal cross-sectional view of an assembledcoalescing element 15 in which a series of annular pleat deformationcontrol ribbons or fillets 16 have been applied to the internal pleatterminations 17 of the annular pleated medium 18. The annular medium issurrounded and supported by cylindircal outer shell 19 havingperforations or fluid flow openings 20 therein. Each end of thecylindrical medium and outer shell assembly is enclosed by an end cap21. At least one of the end caps 21, and frequently both as shownherein, have an opening 22 to enable the fluid to be treated to flowinto the interior of the element.

FIG. 3 shows a segmented axial cross-section of the coalescing elementof FIG. 2 as indicated by the section lines. In FIG. 3 a pleatdeformation control ribbon 16 is shown adhered to the inner pleatterminations 7 and respective adjacent surfaces of each pleat leg 9. Itwill be seen that the substantially rigid ribbon 16'of a cured plasticadhesive will prevent any of the inner pleat terminations 7 from beingforced into contact with an adjacent pleat termination of the filter. Ithas been found that incremental placement of such annular bands of pleatdeformation ribbons 16 along the longitudinal length of a medium 18assembled into a element 15 provides adequate pleat deformation controland consequently protects against pleat pinch-off.

FIG. 4 shows a coalescing element identical to the element 15 shown inFIG. 2 in which a pleat deformation control ribbon or fillet 24 has beenextruded onto the internal terminations of the pleats of the pleatedmedium in a helical or spiral configuration terminating in an annularband 16 near each end of the medium.

FIG. shows an assembled element 29 similar to the element of FIG. 2 inrelation to one suitable set of apparatus used to practice the hereindisclosed method of applying extruded pleat deformation control ribbonsor fillets to a pleated medium.

The apparatus rests on a base surface 26 and consists of elementmovement means 27 and adhesive material heating and extrusion means 28.

The element 29 is placed upon means suitable to rotate the element aboutits axis, such as element support rolls 30 of which only one is shown inFIG. 5 and two are shown in FIG. 6. Each of the support rolls 30 issupported at each of its ends by a shaft 31 and 32 that turns withinsuitable bearing means, not shown, provided in roll support means 33 and34. A drive means, such as sheave 35 is rigidly affixed to at least oneof the rolls 30 and is suitably connected to a rotary motion powersource, such as variable speed electric motor 36, which is connected todriven sheave 35 by driving sheave 37 and drive belt 38.

Roll support means 33 and 34 and the rotary power source means aremounted on a surface 39 capable of movement parallel to the axis offilter element 15. It will be seen that surface 39 is supported abovebase surface 26 by support rolls 40.

A linear motion power source, such as double acting hydraulic cylinder21, is connected to element movement means 27 and moves means 27, withsuitable controls, along surface 26 in a direction parallel to the axisof the element 29. Guide means, such as raised guide way 42 may beprovided to assure proper longitudinal movement of movement means 27. Itwill be readily seen that element support means 27 could be maintainedstationary and nozzle 50 could be rendered capable of movement parallelto the longitudinal axis of the filter element, such as by provision oftelescoping conduit 51 or by arranging for suitable movement of materialheating and extrusion means 28.

Adhesive material heating and extrusion means 28 is comprised ofadhesive reservoir 43 having sealable opening 44, an air inlet 45 andadhesive outlet 46. The reservoir is provided with heating means, suchas an induction heating coil 47 so the contents of the reservoir can bemaintained at a desired temperature. Air inlet 45 is connected to asource of comprssed air by conduit 48.

Adhesive outlet opening 46 is sealingly engaged with an adhesive outletconduit 49 which contains at least one extrusion nozzle 50. Adhesiveoutlet conduit 49 is also preferably provided with a means, such as aninduction heating coil 51, to heat its contents.

Adhesive reservoir 43 is suitably maintained in a fixed positionrelative to filter element 29 by means such as support legs 52.

To practice the method of this invention a heat softening adhesive 53 ismaintained at a desired viscosity in the reservoir 43 by proper controlof heating means 47. The adhesive is maintained under substantiallyconstant pressure by a suitable regulated source of compressed airadmitted to the reservoir through conduit 48 and opening 45.

The pressure of the compressed air forces the adhesive through opening46, conduit 49 and out nozzle 50. Suitable flow control means, such as avalve 54, is preferably provided to enable accurate regulation and rapidcommencement and termination of flow from the nozzle.

To place annular bands such as those shown in FIG. 2 of a pleatdeformation ribbon or fillet about the internal terminations of themedium 61 in element 29, linear motion means 41 moves the element 29 andelement movement means 27 so that the fixed position nozzle 50, isinserted into the interior of the element 29 through opening 63 in theend cap of the element. when the nozzle 50 is adjacent the locationwhere it is desired to place the annular band of pleat deformationcontrol ribbon or fillet the element 29 is rotated about its axis uponsupport rolls 30 by means previously described. Valve 54 is then openedto permit adhesive to be extruded from nozzle 50. Due to gravity theadhesive is deposited in a continuous ribbon onto the internalterminations of the filter medium in element 29 and as the element 29 isrotating a continuous annular band of the adhesive ribbon 64 of FIG. 6is deposited onto those areas of the internal terminations of the mediumwhich pass beneath the nozzle during rotation of the element. Upon acomplete revolution of the element 29 the flow from the nozzle may bestopped by closing valve 54. Longitudinal movement means 41 moves therotating element 29 relative to the nozzle 50 to a next desired locationfor an annular band of pleat deformation control ribbon and theoperation is repeated. A plurality of nozzles may be used forsimultaneous placement of a plurality of annular beads upon the filterelement.

To place a spirally configurated ribbon onto the mediums inner pleatterminations, the element 29 is simultaneously moved longitudinally androtated about its axis while a ribbon of adhesive is extruded from thenozzle 50.

General criteria for suitable materials which may be used to practicethe invention herein disclosed are: (1) it must be a plastic substance,i.e. a substance that at some stage in its manufacture or processing canbe shaped by flow, as by application of heat or pressure, with orwithout fillers, plasticizers, reinforcing agents, or other compoundingingredients and that can retain its new substantially solid shape underconditions of use; (2) it must wet and adhere to the fluid treatmentmedium; (3) it must have sufficient cured strength to maintain thepleats in the desired psition relative to EACH other; (4) it must notdeteriorate when subjected to the fluid being treated or at thetemperatures to which the medium is subjected in use; (5) it must becapable of being rendered sufficiently fluid to enable it to readilyflow from the nozzle, but it must also be sufficiently thixotropic so itmaintains the position in which it is deposited upon the medium, despitesubstantially continual rotation of the element during application ofthe material.

It will be readily apparent to those skilled in the art that a greatvariety of plastic adhesives, such as thermoplastic adhesives,thermosetting adhesives, hot melt adhesives, plastisols, epoxies, andthe like, will be suitable to practice the method and obtain the pleatdeformation control means of this invention.

One representative suitable hot melt plastic adhesive is Ward andKennedy Companys No. 502 Hot Melt. This adhesive is maintained in thereservoir at temperatures within the range of 320 325 F. Additionallythe hot melt contained within the outlet conduit 49 upstream of valve 54is preferably maintained at a temperature of4 1 425 F. The pressure onthe adhesive in the reservoir is maintained at 50 60 psi. Maintainingthe above variables within the ranges mentioned and rotating the elementat 6 rpm provides a desired pleat deformation control means as hereindisclosed.

Another representative suitable plastic adhesive is Co-Polymer ChemicalIncorporateds EA -55 two component, filled epoxy. This epoxy isnon-thixotropic. lts two components are mixed together in equal volumesin a conventional mixing head placed upstream of the nozzle. Onereservoir is required for each component of the epoxy and pump means,such as conventional positive displacement pumps, which will provide acontrolled amount of each component from the reservoir to the mixinghead are required. Neither the reservoirs nor the conduits connectingthe reservoirs to the mixing head need be heated.

It is preferable to pre-heat the medium upon which this epoxy is to beplaced to a temperature in the range of 325 375 F. prior to extrudingthe ribbon or fillet of epoxy onto it. Such pre-heating of the mediumlowers the viscosity of the epoxy and causes it to more readily flowbetween adjacent pleat legs.

Cure of this epoxy may be accelerated by heating in an oven afterapplication, if desired.

1 claim:

1. In a fluid treatment element having an annulus of longitudinallypleated fluid treatment medium surrounded by a perforate cylindricalouter shell and having an end cap at each end of the assembly, at leastone of said end caps having a flow opening communicating with the spacedefined by the inner circumference of the annulus of pleated medium, animproved pleat deformation control means comprising:

a continuous fillet of a rigid plastic adhered to the inner pleatterminations defining the inner circumference of the annular pleatedmedium.

2. The improved pleat deformation control means as defined in claim 1 inwhich said continuous fillet of plastic defines an annular band withrespect to the longitudinal axis of the fluid treatment element.

3. The improved pleat deformation control means as defined in claim 1 inwhich said continuous fillet of plastic defines a helix with respect tothe longitudinal axis of the fluid treatment element.

4. The improved pleat deformation control means as defined in claim 3 inwhich said helix formed from said continuous fillet of plasticterminates in an annular band near each end of said fluid treatmentelement.

5. In a fluid treatment element having an annulus of longitudinallypleated fluid treatment medium surrounded by a perforate cylindricalouter shell and having an end cap at each end of the assembly, at leastone of said end caps having a flow opening communicating with the spacedefined by the inner circumference of the annulus of pleated medium, animproved pleat deformation control means comprising:

a continuous fillet of a hot melt adhesive adhered to the inner pleatterminations defining the inner circumference of the annular pleatedmedium.

6. In a fluid treatment element having an annulus of longitudinallypleated fluid treatment medium surrounded by a perforate cylindricalouter shell and having an end cap at each end of the assembly, at leastone of said end caps having a flow opening communicating with the spacedefined by the inner circumference of the annulus of pleated medium, animproved pleat deformation control means comprising:

a continuous fillet of an epoxy adhered to the inner pleat terminationsdefining the inner circumference of the annular pleated medium.

1 i t i i UNHED STATES PATENT OFFICE v CETiFlCA-{EE OE CRRECTION PatentNo. D ted August l t, 1973 g I Inventor(s) James C, McLaren It iscertified that error appears in the above-identified patent v and thatsaid Letters Patent are hereby corrected as shown below;

Column 1, line 5Q, change "the of th Le" to extrusion of the 0 line 49cancel "is"; 1 line 56, change "of" to to line 24, change "cylindircal"to cylindrical Column 3,

Column A, line 29, change "comprssed" to.

- compressed Column 5, line 28, change "psition" to position 5 r 1 7line 29, change "EACH" to j-- each Signed and sealed this 22nd day ofJanu ry 197A (SEAL) Attest:

EDWARD M.FLETCEER,JE. RENE D, TEGTMEYER- Attesting Officer ActingCommissioner of Patents

2. The improved pleat deformation control means as defined in claim 1 inwhich said continuous fillet of plastic defines an annular band withrespect to the longitudinal axis of the fluid treatment element.
 3. Theimproved pleat deformation control means as defined in claim 1 in whichsaid continuous fillet of plastic defines a helix with respect to thelongitudinal axis of the fluid treatment element.
 4. The improved pleatdeformation control means as defined in claim 3 in which said helixformed from said continuous fillet of plastic terminates in an annularband near each end of said fluid treatment element.
 5. In a fluidtreatment element having an annulus of longitudinally pleated fluidtreatment medium surrounded by a perforate cylindrical outer shell andhaving an end cap at each end of the assembly, at least one of said endcaps having a flow opening communicating with the space defined by theinner circumference of the annulus of pleated medium, an improved pleatdeformation control means comprising: a continuous fillet of a hot meltadhesive adhered to the inner pleat terminations defining the innercircumFerence of the annular pleated medium.
 6. In a fluid treatmentelement having an annulus of longitudinally pleated fluid treatmentmedium surrounded by a perforate cylindrical outer shell and having anend cap at each end of the assembly, at least one of said end capshaving a flow opening communicating with the space defined by the innercircumference of the annulus of pleated medium, an improved pleatdeformation control means comprising: a continuous fillet of an epoxyadhered to the inner pleat terminations defining the inner circumferenceof the annular pleated medium.